Hackaday Links: October 17, 2021

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We found a couple of headlines this week that seemed pretty alarming at first, mentioning as they did both “Chinese grannies” and “stun guns.” Digging a little deeper, it appears that widespread elder abuse isn’t what this is about, although there certainly is an unsavory aspect to the story. Apparently, it’s pretty common in Chinese cities for large groups of people to get together for exercise, with “square dancing” being one popular form. This isn’t the “do-si-do and allemande right” square dancing that made high school gym class really awkward for a few days, but rather large groups of mostly older women busting moves to Chinese music in public spaces. It’s the music that’s bothering some people, enough so that they’re buying “stun guns” that can somehow turn off the dancing grannies’ music. None of the articles go into any detail on the device besides describing it as a flashlight-looking thing, and that it appears to do no permanent damage to the sound system. We’d love to know where to get one of these things — you know, for science. And really, it’s kind of sad that people are taking offense at senior citizens just looking for a bit of exercise and social contact.

A couple of weeks back, we mentioned TeachMePCB, a free online PCB design class designed to take you from zero to PCB designer. We’ve been working through the course material and enjoying it, but it strikes us that there’s a lot to keep track when you’re designing a PCB, especially if you’re new to the game. That’s where this very detailed PCB design checklist would come in handy. It takes you right from schematic review and breadboard testing of subassemblies right through to routing traces to avoid crosstalk and stray capacitance problems, and right on to panelization tips and even how to make sure assembly services get your build right. Reading through the list, you get the feeling that each item is something that tripped up the author (grosdode) at one time or another. So it’s a little like having someone with hard-won experience watching over your shoulder as you work, and that can’t really be a bad thing.

Our friend Jeroen Vleggaar over at Huygens Optics on YouTube posted a video the other day about building an entire Schmidt-Cassegrain reflecting telescope out of a single piece of glass. The video is mostly an interview with optical engineer Rik ter Horst, who took up the building of monolithic telescopes as a hobby. It turns out that one of his scopes will be flying to space aboard a cubesat in January. If you’re a fan of precision optics, you’ll want to check this out. Jeroen also teased that he’ll be building his own version of Rik’s monolithic telescope, so watch for an article on that soon.

Heads up — applications are now being accepted for the Open Hardware Summit’s Ada Lovelace Fellowships. This year there are up to ten fellowships offered, each of which includes a $500 travel stipend to attend the Open Hardware Summit in April. The fellowships seek to foster a more diverse community in open-source hardware; applications are being accepted until December 17th, so hurry.

And finally, if you’ve got some spare cycles, you might want to turn your Mark 1 eyeballs to the task of spotting walrus from space. The World Wildlife Federation (WWF) is crowdsourcing its walrus census efforts by training people to spot the well-armed marine mammals in satellite photos. Assessing population numbers and distribution is important to understanding their ecology, and walrus are cute and cuddly (no, they’re not), so getting people to count them makes sense. But this seems like a job for machine vision — there has to be a model trained to recognize walrus, right? Or maybe just something to count dark spots against a white background? Maybe someone can whip something up to make this job a bit easier and less subjective.

22 thoughts on “Hackaday Links: October 17, 2021

  1. @Dan Maloney said: “…there has to be a model trained to recognize walrus, right?”

    Gee Dan, using “walrus” as a collective plural here sounds a bit awkward to me. Yes we’re counting members of a single species, but collectively each member is an independent entity. Give this a try instead:

    “…there has to be a model trained to recognize walruses, right?”

    Hmmm better, but:

    “…there has to be a model trained to count walruses, right?”

    Yeah, to me that sounds good.

    1. When my wife and I were in GuangDong (Canton) years ago, we wished we could’ve joined the Morning Tai Chi crowd in the park! We certainly would have provided them with some self deprecating entertainment if we had!

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